Improvement in piston-packings



UNITED STATES PATENT OFFICE.

E. fr. rruuDLE, or AURORA, rLLiNoi's.

IMPRVEMENT IN PISTON-PACKINGS.

Specification forming part of Letters Patent No. 57,375, dated August 21, 1366.

To all whom it may concern:

Beit known that `I, E. T. PRINDLE, of Aurora, in the county of Kane and State of Illinois, have invented a new andfImproved Self-Acting Piston-Packing; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making a part ot' this specification, in which- Figurel is a half-sectional view of the piston, showing the steam-inlets through one of the followers. Fig. 2 is a View of the edge of the piston. Fig. 3 is a diainetrical section through the piston. Fig. 4 is an enlarged section of the packin g-rin gs and steam -passages through the followers. Fig. 5 isl an enlarged sectionof a portion of the piston and its rings, showing the pressuresprin gs.

Similar vletters of reference indicate corresponding parts in the several figures.

'This invention relates to a new and improved mode of constructing piston-packing and applying the same to pistons, whereby the packing shall be uniformly expanded by means of steam acting through ports or passages which are made through the followers of the piston.

The nature of my invention consists in applying a number of sectional beveled rings to annular depressions formed in the circumference of the piston in such manner that, by the action of steam through perforated followers upon circular wedges or beveled rings, the sectional rings will be uniformly expanded and set out against the sides of the cylinder in which the piston works, said rings being also acted upon constantly by means of springs in such manner that they shall be held ont against the cylinder by a gentle pressure only when not acted upon by steam, as will be hereinafter described.

To enable others skilled in the art to understand my inrentioinl will describe its construction and operation.

In the accompanying drawings, A represents the circular skeleton ring or rim of the follower, and B B' are the circular followers thereof, which latter are bolted to the central supporting-spokes in any suitable manner.

Ihe rim A is constructed with two annular depressions in its circumference, which are other, and thereby admit of expansion and.

contraction without exposing leaky joints.

Before applying the sectional rings a a tothe piston, I apply within the annular recesses in the rim the circular wedges or beveled rings b b,-as shown in Figs. 3, 4, and 5, which rings are allowed to play back and forth freely. The beveled surfaces of the sectional rings a', a are ltted to the correspondingbevcled surfaces of the rings Zi 1, so that these'latter rings will force the former rings outward by the pressure of steam acting through the ports or perforations c c c, which are made through the followers B B. t y

Each set of the segments or rings aa are made of such width that they will tit snugly but not too tightly in their respective recesses. They maybe connected together by rabbets, as shown in the drawings, and they maybe constructed of any suitable metal which will be found best adapted to the purpose.

The wedge-rings b b may be divided into segments; rings solid, and to make the perforations c c through the followers sufficiently numerous to cause a uniform pressure of steam upon said rings, so that thc segments will beexpanded equally.

In order to keep the circumference of the sectional rings o a pressed against the cylinder within which the piston works when said rings are not acted upon by them, leinploy springs g g g, which are inserted into recesses in the followers B B' and arranged so as to act upon the wedge-rings b b and press the sectional rings outward gently, but not with sufficient force to create undue friction upon the piston. These springs are intended to keep the packing-rings in their places, so that they shall always be in position for being acted upon by the steam through the medium of the rings b b, as above set forth.

but I prefer to have each of these c c and When the piston constructed as above described is placed within a cylinder for which it is adapted, the coiled springs g g will pressy possible `for steam to pass them. After the piston has traveled the length of its stroke, and the steam has been exhausted from -this end of tbe cylinder, there remains no friction on the cylinder from this set of rings, except what little is caused by the pressure ot' the coiled springs gg. The steam entering the opposite side of the piston, the operation of expanding the set of rings on that side isthe same. l

- It will be seen from the above description Athat I employ two sets of sectional packingrings, each set being acted upon by means of springs-g g, through. the medium of circular Wedges, so that the packing-rings are atall times, when thepiston is within a steam cylinder,4pressed outa gainst the bore of such cylinder. v

` The pressure whichis rnecessary to act" upon said packing-rings to prevent the escape v of steam' past them is effected by the steam which lacts to move the piston, and in proper tion as this pressure increases the pressure upon the packing-rings will be increased and the liability of 'team to escape diminished.

Having thus described 'my invention, what I claim as new,fand desire to secure by Letters Patent, is-

1; Thecombination of the sectionalbeveled u packing-'ringen a and wedge-rin'gsb b, placed within annular recesses formedin the circumference.v of a piston, so that Isteanr acting through perfortions c o, through the followers I ofthe piston, shall effect the uniform expansion of the packing, substantially as described.

g 2. The combinationof the two sets of packing-rings a a, the-wedge-rngs b b, and springs g g g, with the skeleton-ring A of the piston andthe perforated followers B B', substantially as described.v

E. T. PRINDLE Witnesses:

A. R. TERWILLIGER, E. SUMWAY. 

